Decoupling Interval Timing and Climbing Neural Activity: A Dissociation between CNV and N1P2 Amplitudes
Decoupling Interval Timing and Climbing Neural Activity: A Dissociation between CNV and N1P2 Amplitudes
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DOI：
10.1523/jneurosci.2523-13.2014
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发表时间：
2014-02-19
影响因子：
5.3
通讯作者：
van Rijn, Hedderik
中科院分区：
文献类型：
--
作者：
Kononowicz, Tadeusz W.;van Rijn, Hedderik
通常认为，攀登神经活动，例如由脑电图中的偶然负变（CNV）所反映的，是主观时间体验的标志。根据这一观点，CNV的解决与主观计时过程的终止相一致。奇怪的是，行为数据表明，即使在标准间隔（SI）已经过去之后，参与者也会跟踪时间。本研究讨论了CNV消退后时间是否继续。在实验1中，人类参与者被要求区分时间间隔，而诱发电位（EP）引起的声音终止比较间隔（CI）进行了测量。由于N1P2分量的幅度作为与SI的时间距离的函数而增加，并且P2分量的潜伏期遵循CI的危险率，因此在CNV解决后，计时过程继续。基于一种新的实验范式，统计模型比较和试验的试验分析，实验2支持这一发现的主观时间更准确地索引的振幅早期EP比CNV振幅。这些结果提供了第一个直接的证据表明，主观计时的多秒间隔不依赖于攀登神经活动的CNV指数和主观经验的时间更好地反映了CI后诱发电位的独特功能。
It is often argued that climbing neural activity, as for example reflected by the contingent negative variation (CNV) in the electroencephalogram, is the signature of the subjective experience of time. According to this view, the resolution of the CNV coincides with termination of subjective timing processes. Paradoxically, behavioral data indicate that participants keep track of timing even after the standard interval (SI) has passed. This study addresses whether timing continues after CNV resolution. In Experiment 1, human participants were asked to discriminate time intervals while evoked potentials (EPs) elicited by the sound terminating a comparison interval (CI) were measured. As the amplitude of N1P2 components increases as a function of the temporal distance from the SI, and the latency of the P2 component followed the hazard rate of the CIs, timing processes continue after CNV resolution. Based on a novel experimental paradigm, statistical model comparisons and trial-by-trial analyses, Experiment 2 supports this finding as subjective time is more accurately indexed by the amplitude of early EPs than by CNV amplitude. These results provide the first direct evidence that subjective timing of multisecond intervals does not depend on climbing neural activity as indexed by the CNV and that the subjective experience of time is better reflected by distinct features of post-CI evoked potentials.